1. Field of Invention
This invention relates to ensuring ventilation passage in a fluid container while preventing fluid leakage.
2. Description of Related Art
Fluid ejector systems, such as drop-on-demand liquid ink printers, have at least one fluid ejector from which droplets of fluid are ejected towards a receiving sheet. Scanning inkjet printers are equipped with fluid ejection heads containing fluid ink. The ink is applied to a sheet in an arrangement based on print data received from a computer, scanner or similar device.
The fluid ejection heads are designed to be filled with fluid, such as ink, and sealed for transport until usage. A vent port enables excess ullage (from increasing internal pressure of the gas layer) in the fluid ejection heads during transport to be vented. Vapor lock can inhibit the flow of fluid from the fluid ejection head if the discharged fluid is not replaced by air once the exit pressure reduces to ambient pressure. Vapor lock is thus avoided by ventilating the fluid ejection head during ejection operation.
However, the fluid ejection heads can be oriented in any direction both during transport and when the seals are removed. Under some orientations, the fluid in the fluid ejection heads can migrate to block the ullage from access to the ventilation port, thus inhibiting proper ventilation.
Additionally, the barometric pressure and ambient temperature conditions in which the fluid ejection heads experience during storage and/or shipping can cause volumetric expansion of the fluid. Such expansion can cause a portion of the fluid to seep into the ventilation port and thereby contaminate regions outside the printhead with the fluid.